THERMAL-CHARACTERISTICS OF 10 ANDEAN LIZARDS OF THE GENUS LIOLAEMUS IN CENTRAL CHILE

We studied the ecology of ten species of tropidurid lizards in the gen us Liolaemus on an altitudinal transect in the central Chilean Andes, from 1500 to 3000 m elevation, to determine whether physiological Fact ors may be setting distribution limits. Detailed data on thermal biolo gy are presented here. There was a lack of association between lizard thermal tolerance and elevation, thus suggesting that these temperatur e relationships did not set distributional limits within the elevation s of the study transect. Some physical factors did influence the therm al biology of Liolaemus. Body mass determined thermal inertia, thus in fluencing rates of cooling and heating. Larger body size and its conse quent thermal inertia in part may determine diel activity periods, wit h smaller individuals active earlier and larger individuals active lat er. Non mass-related differences in heating rates also existed among t he species: those at higher elevations heated more slowly. The cooler ambient temperatures at higher elevations did not produce interspecifi c differences in body temperature, but most high-elevation species sho wed an intraspecific decrease in body temperature with elevation.